Why is the RGBA result approximate?

CMYK and RGB occupy different color gamuts. CMYK describes print pigments, while RGBA is based on the additive RGB model used by screens. Some print colors may not display identically on screen due to gamut differences.

What is the Key (K) channel in CMYK?

K stands for Key, which represents black ink. A dedicated black channel produces deeper blacks and reduces overall ink cost compared to mixing equal amounts of Cyan, Magenta, and Yellow.

How is CMYK converted to RGBA?

CMYK is converted to RGB using the formulas R = 255 × (1 − C/100) × (1 − K/100), G = 255 × (1 − M/100) × (1 − K/100), and B = 255 × (1 − Y/100) × (1 − K/100). The Alpha channel is independent and set separately.

What does the Alpha value control?

Alpha controls transparency. A value of 1 means fully opaque, while 0 means fully transparent. Values between 0 and 1 produce semi-transparent colors, useful for overlays and blending effects in CSS and canvas.

Are the RGBA values suitable for use in CSS?

Yes. The output rgba() string can be pasted directly into any CSS property that accepts a color value, such as background-color, color, or border-color.

What does K=100 produce?

K=100 with any C, M, Y values produces pure black: rgba(0, 0, 0, 1). All channels at 0 produce pure white: rgba(255, 255, 255, 1).

CMYK to RGBA Converter

Name: CMYK to RGBA Converter
Availability: InStock
Author: Nham Vu

Enter CMYK percentages and instantly get the equivalent RGBA values with a live color preview swatch.

CMYK Input

Cyan (%) 0 – 100

Magenta (%) 0 – 100

Yellow (%) 0 – 100

Key / Black (%) 0 – 100

Alpha 0 – 1

RGBA Output

rgba(58, 183, 204, 1)

Red

Green

Blue

Alpha

Ink Coverage 0%

Sum of all four ink channels (C+M+Y+K)

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Summary

Enter CMYK percentages and instantly get the equivalent RGBA values with a live color preview swatch.

How it works

Enter Cyan, Magenta, Yellow, and Key (Black) percentages (0–100) in the input fields.
Adjust the Alpha slider (0–1) to set the transparency level.
The RGBA values and color preview swatch update instantly as you type.
Use the sliders for quick visual adjustment of each channel.
Click any Copy button to copy individual channel values or the full rgba() string.

Use cases

Translate print-spec CMYK colors into CSS-ready rgba() values.
Cross-reference brand color specifications between print and web.
Convert CMYK values from design files into RGBA for CSS stylesheets.
Add transparency control to a color originally defined in CMYK.
Validate that a print color matches the intended on-screen appearance.
Quickly obtain RGBA color strings for use in canvas, SVG, or design tools.

Frequently Asked Questions

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Last updated: 2026-05-28 · Reviewed by Nham Vu